Holley 558-416 Main Harness Fuel Wiring Harness Adapter, Replacement with 12 Month Warranty & Made in USA

Upgrade your LS engine wiring configuration with the Wholesale Sensors Replacement for Holley 558-416 LS Main Harness to LS3-Style MAP Sensor Adapter. Made in the USA and engineered as a perfect OEM-style replacement, this wiring harness adapter is designed to meet or exceed original functional specifications while providing a clean, reliable electrical connection between a compatible LS1/LS2-style MAP sensor harness connection and an LS3-style MAP sensor.

Whether you are completing an LS engine swap, installing an LS3-style intake manifold, upgrading to a Holley Hi-Ram intake, or replacing a damaged MAP sensor adapter harness, this Wholesale Sensors replacement provides a straightforward solution without unnecessary modification to a compatible main harness.

Replacement for Holley 558-416

This Wholesale Sensors wiring harness adapter is designed as a direct replacement for Holley EFI part number 558-416.

Holley identifies 558-416 specifically as an LS Main Harness to LS3-Style MAP Sensor Adapter. Holley EFI LS main harnesses use a MAP sensor connector designed around the LS1/LS2-style MAP sensor. The 558-416 adapter allows an LS harness using that LS1/LS2 connection to connect to an LS3-style MAP sensor. Holley

This distinction is important when choosing the correct harness. The 558-416 is not a complete engine harness or fuel pump harness. It is an auxiliary MAP sensor adapter harness used within compatible LS EFI configurations. Holley’s specifications classify the original 558-416 as an auxiliary harness for LSX applications with two connectors. Holley

LS1 and LS2 to LS3 MAP Sensor Conversion

The primary purpose of the 558-416 adapter is to simplify conversion between different generations of GM LS MAP sensor connectors.

One end interfaces with the compatible LS1/LS2-style MAP sensor connection, while the other provides the connection needed for an LS3-style MAP sensor. This allows engine builders to combine compatible LS wiring and intake components without cutting apart the existing Holley EFI main harness.

Holley specifically recommends the 558-416 adapter when an LS EFI main harness using the LS1/LS2 MAP connection needs to operate with an LS3 MAP sensor. Holley also identifies it as useful with LS Hi-Ram intake manifolds that require an LS3 MAP sensor. Holley

The original Holley configuration uses 3-pin connectors, and the harness comes pre-terminated for straightforward installation. JEGS High Performance

Compatible GM LS Engine Applications

The 558-416 is best considered engine and EFI-system specific rather than vehicle-year specific. It can be used across different vehicle platforms when the engine, MAP sensor, and EFI harness combination requires the specified LS1/LS2-to-LS3 MAP connection.

Documented engine-family applications include compatible GM Gen III and Gen IV LS engines, including configurations based on LS1, LS2, LS3, LS6, LS7, LS9, LSA, and LSX engines. LMPerformance

This makes the adapter particularly useful for:

LS engine swaps into classic cars and trucks, GM performance builds, LS3 intake conversions, Holley EFI installations, custom street vehicles, race cars, restomod projects, and LS Hi-Ram intake installations.

Because LS engines are frequently swapped between vehicles and modified with components from different generations, compatibility cannot reliably be determined by vehicle make, model, and year alone.

Before ordering, verify that your existing harness uses an LS1/LS2-style MAP sensor connector and that your installation requires connection to an LS3-style MAP sensor.

Compatible Holley EFI Applications

The 558-416 adapter is specifically designed around Holley EFI LS main harnesses. Holley documentation lists the 558-416 as an LS MAP sensor adapter harness and identifies it as an optional component within compatible EFI configurations. Holley Documents

It is commonly associated with Holley performance EFI product families such as HP EFI, Dominator EFI, Terminator, and compatible Terminator X LS applications, provided the actual LS main harness and MAP sensor combination requires this adapter. JEGS likewise catalogs 558-416 within Holley Avenger, HP, Terminator, and Dominator EFI wiring harness applications. JEGS High Performance

Always verify the specific EFI harness before ordering because not every Holley system requires the same MAP connector.

Made in the USA Construction

The Wholesale Sensors replacement for Holley 558-416 is Made in the USA using automotive-grade components selected for dependable operation in demanding performance applications.

The harness incorporates durable insulated wiring, precision electrical terminals, and secure molded connectors designed to maintain a reliable MAP sensor connection. Each harness is rigorously tested for electrical continuity, connector fit, terminal retention, wiring integrity, and signal consistency before shipment.

Reliable electrical connections are especially important for MAP sensor operation because Holley EFI systems use MAP sensor information as part of their speed-density engine management strategy. A poor electrical connection can interfere with the signal reaching the EFI system.

Simple Plug-and-Play Installation

The pre-terminated design helps eliminate unnecessary cutting or modification of the compatible LS EFI main harness. JEGS describes the original 558-416 configuration as a plug-and-play, pre-terminated harness that converts the LS1/LS2 MAP connector to LS3 style. JEGS High Performance

Disconnect vehicle power before performing electrical work. Inspect both MAP sensor connectors for corrosion, damaged terminals, bent pins, broken locking tabs, or previous wiring modifications.

Connect the adapter between the compatible LS1/LS2-style harness connection and LS3-style MAP sensor, confirm that both connectors are fully seated and locked, then route the wiring away from exhaust components, sharp edges, belts, pulleys, and other moving components.

No cutting or splicing should be necessary when the correct compatible components are being used.

Important Diagnostic Information

If your engine has a MAP sensor-related diagnostic trouble code, replacing the adapter harness should only be considered when inspection or electrical testing indicates a wiring or connector problem.

MAP sensor faults can also result from a defective MAP sensor, damaged main harness, poor electrical connection, vacuum or intake problems, incorrect sensor calibration, EFI configuration errors, or other engine management issues.

For that reason, this adapter should not be advertised as a guaranteed fix for a specific OBD-II trouble code.

12-Month Warranty and USA-Based Support

Wholesale Sensors provides dependable replacement sensors, connectors, pigtails, and wiring solutions for automotive, performance, commercial, and industrial applications.

The Wholesale Sensors Replacement for Holley 558-416 LS Main Harness to LS3 MAP Sensor Adapter combines Made in USA construction, pre-terminated connections, LS engine compatibility, straightforward installation, and rigorous electrical testing.

Every harness is backed by a strong 12-month warranty and responsive USA-based product support, making it a dependable choice for professional engine builders, performance shops, LS swap enthusiasts, racers, restoration specialists, automotive technicians, and DIY builders completing compatible LS EFI installations.